Sometimes the annotation text is upside down.

[servetg]

That's because the loading of texture coordinate matrix has been omitted.
A solution would be:

1. texCoordMatrix initialization in Annotation's constructor
   line 115:
   // Internal use only. Intentionally not documented.
   this.texCoordMatrix = Matrix.fromIdentity();

2. texCoordMatrix loading in Annotation.prototype.doDrawOrderedAnnotation, after program.loadTextureEnabled(gl, textureBound);
   line 513:
   this.texCoordMatrix.setToIdentity();
   this.texCoordMatrix.multiplyByTextureTransform(this.labelTexture);
   program.loadTextureMatrix(gl, this.texCoordMatrix);

[pdavidc]

Servet, Thanks for investigating this issue. The team has reviewed your proposal, and would like to get this fix in the repository. Would you please put together a fix and commit it to the develop branch?

[servetg]

Dave, I've made a pull request containing a fix for this bug.

[pdavidc]

Fix is in pull request #85